Erectile Dysfunction Drug May Relieve Neuropathy

New research conducted at Henry Ford Hospital, and published online in PLOS ONE reports that sildenafil, a drug commonly used to treat erectile dysfunction, may be effective in relieving painful and potentially life-threatening nerve damage in men with long-term diabetes. Diabetic peripheral neuropathy is a common complication of diabetes, affecting up to 70% of diabetes patients. Lead researcher Lei Wang, MD, noted that this study differed from previous research in that most used young diabetic animals with early stage peripheral neuropathy. Patients with diabetes who are enrolled in clinical trials, however, are often older and have advanced peripheral neuropathy. This discrepancy may explain why numerous drugs that have been shown to be effective in earlier animal experiments, have not provided benefits in clinical trials.

Earlier animal experiments from the Henry Ford group showed that sildenafil, commonly known by the brand name Viagra®, improved blood supply to the sciatic nerve. In addition, it was noted that diabetes patients who took Viagra for erectile dysfunction had fewer symptoms of peripheral neuropathy. But the existence of long-term therapeutic benefit had yet to be tested. To mimic clinical trials in which diabetes patients have advanced peripheral neuropathy, the researchers chose male mice with type II diabetes that were 36 weeks old, roughly equivalent to middle age in humans. The authors report significant improvement in neurological function and, while stressing the preliminary nature of the findings, assert that they may lead to the development of a sildenafil treatment for long-term diabetic peripheral neuropathy.